Crossover device for parallel pipe strings



Sheet H. U. GARRETT cRosso'vER DEVICE FOR PARALLEL PIPE STRINGS AJuvly8, 1969 Filed Jan. 29, 1968 Arrow/ys July 8 1969 l H. u. GARRETT3,454,096

I CROSSOVER DEVICE FOR PARALLEL PIPE STRINGS med Jan. 29, 196s sheet 2of /Ofu- "rh-a Hfwmmf" 7. l HY ATT ORNEKS United States Patent Ar U.S.Cl. 166-242 7 Claims ABSTRACT F THE DISCLOSURE A crossover deviceadapted for connection into a plurality of parallel pipe strings toprovide means for opening communication `between the pipe strings whennecessary to establish cross-flow between the pipe strings.

In the operation of oil and gas wells, it is frequently necessary, afterthe wells have been in operation for various periods of time, to performvarious operations in the production strings to improve the functioningthereof. Such operations may include installing or actilvatingartificial lift equipment, cleaning out paraffin deposits, removingaccumulating sand and other detritus which may plug the production pipestring, and various other operations familiar to those engaged in oilwell operations.

While the performance of such servicing operations in wells located onland usually involve various diticulties and complexities, the latterare greatly increased in wells in offshore locations. To meet theservice and workover requirements for such Wells with minimum diiiicultyand expense, various types of servicing systems have been devised.

In one such system installed as part of the original well equipment,parallel pipe strings are run into a well, one or more of such pipestrings being equipped to function as production strings and one or moreadditional pipe strings equipped to function as service strings, thepipe strings being frequently interchangeable as to function. Byproviding a service pipe string in communication with a production pipestring, fluids under pressure may be circulated from one string to theother to remove obstructions, to clean out sand and paraiiin, and toperform other operations in which such circulating uids may be useful.

In such multiple string systems, an open crossover connection -willusually be provided between the strings adjacent their lower ends sothat initially a uid circulation path may be established between thestrings as may be required. v

However, it is found that in the course of operation, plugging by parainor sand, or some other defect or difficulty may occur at one or morepoints in the production string above the lower ends of the pipe stringsand it -becomes necessary in some manner to establish cross-flow betweenthe pipe strings at points below or between such plugged -or obstructedpoints, so that pressure uid may be circulated from the -service stringinto the production pipe string at the elevation most effective toeliminate the difliculty.

The present invention is directed to a form of crossover device adaptedto meet and overcome such prob- 3,454,096 Patented July 8, 1969 ice lemsand comprises a body having a plurality of parallel bores andconstruction to be installed in a corresponding plurality of parallelpipe strings. The body of the device is provided with crossover passagemeans disposed to connect the several bores, but which initially issealed oli` from communication with at least one of said bores, so thatupon opening communication between the latter and the crossover passage,as by operation of a perforating device in the sealed-olf bore,cross-communication may be established between the several pipe strings.

The crossover device includes a positioning or indexing seat forreceiving a perforating tool or the like, in a manner to indexthe'perforating tool at a position enabling it, -When actuated, to forman opening through the wall of the sealed-oli bore into the crossoverpassage.

In the case of a dual pipe string system, an opening will ordinarily -bepre-formed between the -bore of the production string and the crossoverpassage, and communication established with the service pipe string,when required, by perforating the latter to provide communication withthe crossover passage.

Ordinarily, a plurality of such crossover devices will be initiallyinstalled at longitudinally spaced points along the parallel strings, sothat a plurality of spaced crossover points will be provided at 4whichfluid communication between the several pipe strings may be establishedas determined by conditions fwhich may develop during the course ofoperation of the well.

Other and more specific objects and advantages of this invention will'become more readily apparent from the following detailed descriptionwhen read in conjunction with the accompanying drawing which illustratesone useful embodiment in accordance with this invention.

FIG. 1 is a longitudinal -sectional view of a parallel dual pipe stringsystem having installed therein a crossover device in accordance withthis invention, and showing positioned in one of said pipe strings aperforating tool in position to form a perforation to establishcornmunication with the crossover passage in the device;

FIG. Z is a View similar to FIG. 1, showing the perforation formed bythe perforating tool;

FIG. 3 is an elevational view, partly in section, showing a dual pipestring system in a well, and provided with a pluurality oflongitudinally spaced crossover devices in accordance with thisinvention; and

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2.

Referring iirst to FIG. 3, there is shown a dual parallel pipe system,designated generally by the letter S, installed in a well bore W. SystemS comprises a pair of parallel pipe strings 10 and 11. Pipe string 10may be designated for purposes of this description as a production pipestring, and pipe string 11 as the service pipe string. Adjacent theirlower ends pipe strings 10 and 11 are connected by an open crossoverconnection 12 having a pair of parallel passage means 13 and 14 definingdownward extensions of the respective pipe strings 10 and 11. Thepassage means 13 and 14 are closed by means of upwardly opening checkvalves 15 and 16, respectively, commonly referred to as standing valvesthrough which production fluids may enter the respective pipe stringsfrom producing formations intersected by the well bore.

A number of crossover devices, designated generally by the letter C andconstructed generally in accordance with this invention, are positionedat vertically spaced points along the pipe system connected into bothpipe strings and 11. As best shown in FIGS. l, 2 and 4, each of thesecrossover devices C comprises a generally tubular body, designatedgenerally by the numeral 20, comprising telescopically interconnectedupper and lower body sections 21 and 22, respectively. Body 20 isprovided with a pair of parallel sleeves 23 and 24 having the respectivebores 23a and 24a coaxial, respectively, with pipe strings 10 and 11.The upper ends of sleeves 23 and 24 are formed to provide internallythreaded sockets 25 and 26, respectively, which connect into therespective pipe strings 10 and 11. The lower ends of sleeves 23 and 24likewise communicate with internally threaded sockets 27 and 28,respectively, provided in lower body section 22. The upper portion oflower body section 22 is dened yby an annular wall 29 which isthreadedly connected to upper body section 21 at 30 and surroundssleeves 23 and 24 to define an annular crossover passage 31 extendingcircumferentially about both sleeves 23 and 24. The wall of sleeve 23 isinitially provided with a pre-formed opening 32 placing bore 23a intocommunication -with crossover passage 31. The other sleeve 24 isimperforate and, therefore, initially out of communication with thecrossover passage but is placed in communication therewith in a mannerto be subsequently described.

Sockets 27 and 28 in lower body section 22 are adapted to receive thethreaded upper ends of tubular latch mandrels 33 and 34, respectively,the lower ends of which carry externally threaded pins 35 and 36,respectively, for connection to lower sections of the respective pipestrings 10 and 11. Mandrels 33 and 34 are provided with enlarged boreportions 37 and 38, respectively, coaxial with the bores of the mandrelsand the respective bores 23a and 24a and their related pipe strings 10and 11. The enlarged bore portions 37 and 38 are each dened by a lowerend "wall 39 and an upper end wall 40, the latter being downwardly andinwardly bevelled, as shown. Enlarged bore portions 37 and 38 providelatching seats for reception of perforating tools, as will besubsequently described.

Operation of the dual pipe `string system may require that iluidcirculation be established between pipe strings 10 and 11 at pointsabove crossover connection 12, for whatever purposes needed. In suchcase, a perforating tool of generally conventional design, designatedgenerally by the numeral 45, will be run through the bore of servicepipe string 11 to a position in bore 24a opposite passageway 31. Toaccomplish this positioning of the perforating tool, the lower end ofthe latter will be conneced to a known form of cam latch, designatedgenerally by the numeral 46, which forms no part of the presentinvention but is illustrated in a form which enables perforating tool 45to be latched into bore enlargement 38 in a position to dispose theperforating element, indicated at 47, `adjacent the wall of sleeve 24and opposite passageway 31. It will be understood that the perforatingtool, the latch mechanism, and the fishing head 49 by which the tool isinserted into and withdrawn from pipe string 11, are generallyconventional and the details thereof do not form any part of the presentinvention.

When perforating tool 45 has been positioned as described andillustrated, it will be tired in a generally conventional manner, eitherby electrical or hydraulic means, so as to cause the perforating element47 to form a perforation 48 through the wall of sleeve 24 to place bore24a in communication with crossover passage 31. When this has occurredit will be evident that iluid communication will now be establishedthrough crossover passage 31 between bores 23a and 24a, so that pressureuid may be circulated down through pipe string 11, thence throughcrossover device C into the bore of pipe string 10, and thence backtoward the surface, in order to lift or wash out any obstruction whichit is desired to remove from the production pipe string 10.

By employing a number of crossover devices C at a plurality of pointsalong the pipe string system, circulation may thus be established at anyone or more of these several points between these pipe strings.

It will be understood that the crossover devices in accordance with thisinvention may be made to accommodate more than two parallel pipestrings. In each instance, however, the crossover device willincorporate as many parallel sleeves as may be required to connect it tothe several pipe strings. At least one of the sleeves initially will beimperforate and out of communication with the crossover passage, so thatcommunication may be subsequently established, as required, between theseveral pipe strings. Initially only one of the pipe strings will have apre-formed opening communicating with the crossover passage, although itmay be useful in some cases, where more than two pipe strings areinvolved, to have more than one of the bores in the crossover deviceinitially open to the crossover passage.

It will -be understood that various other modifications and variationsmay be made in the details of the illustrative embodiment within thescope of the appended claims but without departing from the spirit ofthis invention.

What I claim and desire to secure by Letters Patent is:

1. A crossover device for connecting parallel pipe strings, comprising:

(a) a body having a plurality of parallel bores therethrough forconnection into a corresponding number of parallel pipe strings,

(b) a lateral passage in the body extending between said bores,

(c) an opening communicating said passage with one of said bores, and

(d) means in each of the other bores constructed and arranged to locatea perforating tool therein in a position to provide, when actuated, anopening cornmunicating that one of said other bores with said passage.

2. A crossover device according to claim 1, wherein the number of saidparallel pipe strings is two.

3. A crossover device according to claim 1, wherein said means comprisescylindrically enlarged portions of said bores defining seats forlatching engagement by said perforating tool.

4. A crossover device according to claim 1, wherein `said passagecomprises an annular passage extending circumferentially of said bodyexteriorly of said bores.

5. An equipment system for wells, comprising the combination of:

(a) a plurality of parallel pipe strings extending into a Well bore,

`(b) an open crossover connection member connecting said pipe stringsadjacent their lower ends,

(c) said connection member including extensions coaxial respectivelywith said pipe strings and having upwardly opening check valve meanstherein,

(d) crossover devices connecting said pipe strings at one or morevertically spaced points above said crossover connection member, each ofsaid crossover devices comprising:

(i) a body having a plurality of parallel bores therethrough forconnection into the several said pipe strings,

(ii) a lateral passage in the body extending between said bores,

(iii) an opening communicating said passage with one of said bores, and

(iv) means in each of the other bores constructed and arranged to locatea perforating tool therein in a position to provide, when actuated, anopening communicating that one of said other bores with said passage.

6. An equipment system according to claim 5, wherein 3,012,608 12/ 1961McLaren 166-52 the number of said pipe strings is two. 3,050,121 8/ 1962Garrett et al. 166--21 X 7. In an equipment system according to claim 5,said 3,054,456 9/ 1962 Hammaker 166-102X means comprising acylindrically enlarged portion of said 3,086,592 4/ 1963 Hach 166-67 Xbore dening a seat for latching engagement -by said 5 3,149,671 9/ 1964Alexander 166-55.1 X perforating tool.

References Cited DAVID H. BROWN, Primary Examiner.

UNITED STATES PATENTS Us' CL XR 2,923,357 2/1960 Dafn 166-102 166-102,115, 314

2,939,533 6/1960 Coberly 16s-242x 1

